Telephone-transmitter



(No'ModeL) 4 R. P. GREEN. TELEPHONE TRANSMITTER No. 567,132. Patented Sept. 8, 1896.

ATTORNE m ENS r0, PnoraLrmcm/AsmNmoN u c UNITED STATES P TENT OFFICE.

ROBERT P. GREEN, OF COLUMBUS, OHIO.

I TELEPHONE-TRANSMITTER.

SPECIFICATION forming part of Letters Patent No. 567,132, dated September 8, 1896.

Application filed May 31, 1895. Renewed February 12, 1896- Serial No. 579,103. (No model.)

To all whom it may concern:

Be it known that I, ROBERT P. GREEN, a citizen of the United States, residing at O0 lumbus, in the county of Franklin and State of Ohio, have invented a certain new and usef 111 Improvement in Telephone-Transmitters, of which the following is a specification.

My invention relates to the improvement of telephone-transmitters; and the objects of my invention are to provide a transmitter of this class of superior construction and arrangement of'parts, to construct the same in a simple, inexpensive, and effective manner, and to produce other improvements in details of construction and arrangement of parts, which will be more fully pointed out hereinafter. These objects I accomplish in the manner illustrated in the accompanying drawings, in which- Figure 1 represents a central vertical section of my improved transmitter. Fig. 2 is an enlarged central vertical sectional view of the inner or secondary diaphragm; and Fig. 3 is a View in elevation of said secondary diaphragm, showing one of the face-plates removed therefrom.

Similar letters refer to similar parts throughout the several views.

In the construction of my device I employ an outer or main diaphragm a, of thin sheet metal or other suitable material, thelatter being secured over the enlarged mouth portion I) of a recess 1), formed in a suitable transmitter-block c, of non-conducting material.

The main diaphragrn plate a has extending from its center and projecting into the recess b a metallic stem cl. To the inner end of this stem d is secured the central portion of the metallic backing-plate cl of the inner or secondary diaphragmd In constructing the secondary diaphragm I secure to the inner face of said plate 61, adjacent to its edge portions, a frame or gasket 6, preferably formed of paper or pasteboard, but which may be formed of any suitable non-conducting material. is formed within said frame, which said space I fill with granular sulfid of copper or other suitable conducting substance 6. Over the In this manner a shallow cup or recess open side of the receptacle or cup formed as above described I secure a metallic plate f, corresponding with the plate cl.

g and g represent, respectively, the batterywires, one of ,which leads from the plate f and the remaining one of which leads from the main diaphragm a. Over the outer face of the main diaphragm and against the block Although I have shown and described herein.

a form of mouthpiece and transmitter frameblock, it is evident that these parts may be changed or altered as desired Without affecting my invention.

What I claim, and desire to secure by Letters Patent, is-- 1. In atelephone-transmitter the combination of the main diaphragm a, a conductingpin secured to and projecting from said main diaphragm, an inner or secondary diaphragm consisting of two conducting-plates the inner faces of said plates being separated by a frame of non-conducting material, a filling of granular conducting substance between said plates, a wire leading from the secondary diaphragm and a Wire leading from the main diaphragm, substantially as and for the purpose specified.

2. In a telephone-transmitter the combination with a main diaphragm, a mouthpiece in front of the same and a pin projecting inward from said main diaphragm opposite said mouthpiece-opening, of an inner or secondary diaphragm consisting of two conductingplates 01 and f, a filling of granular sulfid of copper between said plates, one of said plates being secured to and supported from the pin 61 and wires g 9 leading respectively from the main and secondary diaphragms,substantially as and for the purpose specified.

ROBERT P. GREEN.

In presence of- C. O. SHEPHERD, A. L. PHELPs. 

